Stress evolution during molecular-beam epitaxy of AIN films was monitored with in situ curvature measurements. Changes in the growth rate produced large stress variations, with more tensile stress observed at higher growth rates. For example, at a growth temperature of 750°C the instantaneous steady-state stress in films with similar grain sizes varied from 0.15GPa at a growth rate of 90nmh, to approximately 1.0GPa at a growth rate of 300nmh. To explain these results, we develop a kinetic model of stress evolution that describes both tensile and compressive mechanisms. The tensile component is based on a mechanism which is proposed here as an inherent feature of grain-boundary formation. The compressive component is based on our recent model of atom insertion, driven by the excess chemical potential of surface adatoms that is created by the growth flux. The combined model predicts that the stress is largely governed by the competition between tensile and compressive mechanisms, which can be conveniently described with a single parameter, α. The limiting values α0 and α+ correspond to previous models of compressive and tensile stresses, respectively.

1.
R.
Abermann
and
R.
Koch
,
Thin Solid Films
129
,
71
(
1985
).
2.
A. L.
Shull
and
F.
Spaepen
,
J. Appl. Phys.
80
,
6243
(
1996
).
3.
J.
Floro
,
S. J.
Hearne
,
J. A.
Hunter
,
P.
Kotula
,
E.
Chason
,
S. C.
Seel
, and
C. V.
Thompson
,
J. Appl. Phys.
89
,
4886
(
2001
).
4.
R. C.
Cammarata
,
T. M.
Trimble
, and
D. J.
Srolovitz
,
J. Mater. Res.
15
,
2468
(
2000
).
5.
S.
Nijhawan
,
J.
Rankin
,
B. L.
Walden
, and
B. W.
Sheldon
, in
MRS Symposia Proceedings Vol. 505
, edited by
R.
Cammarata
 et al (
Materials Research Society
, Pittsburgh, PA,
1998
), p.
415
.
6.
W. D.
Nix
and
B. M.
Clemens
,
J. Mater. Res.
14
,
3467
(
1999
).
7.
L. B.
Freund
and
E.
Chason
,
J. Appl. Phys.
89
,
4866
(
2001
).
8.
S. C.
Seel
,
C. V.
Thompson
,
S. J.
Hearne
, and
J. A.
Floro
,
J. Appl. Phys.
88
,
7079
(
2000
).
9.
S. C.
Seel
and
C. V.
Thompson
,
J. Appl. Phys.
93
,
9038
(
2003
).
10.
A.
Rajamani
,
B. W.
Sheldon
,
E.
Chason
, and
A. F.
Bower
,
Appl. Phys. Lett.
81
,
1204
(
2002
).
11.
A.
Rajamani
,
B. W.
Sheldon
,
S.
Nijhawan
,
J.
Rankin
,
A. F.
Schwartman
,
L.
Riester
, and
B. L.
Walden
,
J. Appl. Phys.
96
,
3531
(
2004
).
12.
E.
Chason
,
B. W.
Sheldon
,
L. B.
Freund
,
J. A.
Floro
, and
S. J.
Hearne
,
Phys. Rev. Lett.
88
,
156103
(
2002
).
13.
B. W.
Sheldon
,
A.
Ditkowski
,
R.
Beresford
,
E.
Chason
, and
J.
Rankin
,
J. Appl. Phys.
94
,
948
(
2003
).
15.
C.
Friesen
and
C. V.
Thompson
,
Phys. Rev. Lett.
89
,
126103
(
2002
).
16.
C.
Friesen
,
S. C.
Seel
, and
C. V.
Thompson
,
J. Appl. Phys.
95
,
1011
(
2004
).
17.
R. W.
Hoffman
,
Phys. Thin Films
3
,
211
(
1966
).
18.
F. A.
Doljack
and
R. W.
Hoffman
,
Thin Solid Films
12
,
71
(
1972
).
19.
L. B.
Freund
and
S.
Suresh
,
Thin Film Materials
(
Cambridge University Press
, Cambridge,
2004
).
20.
C.-H.
Chiu
and
H.
Gao
,
Int. J. Solids Struct.
30
,
2983
(
1995
).
21.
B. W.
Sheldon
,
K. H. A.
Lau
, and
A.
Rajamani
,
J. Appl. Phys.
90
,
5097
(
2001
).
22.
S. J.
Hearne
and
J. A.
Floro
,
J. Appl. Phys.
97
,
014901
(
2005
).
23.
A.
Rajamani
,
R.
Beresford
, and
B. W.
Sheldon
,
Appl. Phys. Lett.
79
,
3776
(
2001
).
24.
K. S.
Stevens
,
A.
Ohtani
,
M.
Kinniburgh
, and
R.
Beresford
,
Appl. Phys. Lett.
65
,
321
(
1994
).
25.
E.
Chason
and
B. W.
Sheldon
,
Surf. Eng.
19
,
387
(
2003
).
26.
V.
Ramaswamy
, Ph.D. thesis,
Stanford University
,
2000
.
27.
C.
Friesen
and
C. V.
Thompson
,
Phys. Rev. Lett.
93
,
056104
(
2004
).
28.
J. A.
Venables
,
Introduction to Surface and Thin Film Processes
(
Cambridge University Press
, Cambridge,
2000
).
29.
M. F.
Doerner
and
W. D.
Nix
,
CRC Crit. Rev. Solid State Mater. Sci.
14
,
225
(
1988
).
You do not currently have access to this content.